Diagnosing pulmonary aspergillosis is much easier than it used to be: a new diagnostic landscape

Abstract

Significant innovations in the past decade have resulted in more sensitive and faster diagnosis of allergic, chronic and invasive pulmonary aspergillosis, as well as Aspergillus bronchitis and Aspergillus nodules. This new diagnostic landscape has revealed that the incidence and prevalence of aspergillosis is substantially higher than previously understood, and is summarised in this review. Oral and intravenous antifungal treatment offers good clinical response rates for affected patients. Nevertheless, missed diagnoses mean that patients are over-treated with antibacterial agents, corticosteroids and anti-TB drugs, resulting in continuing illness and often death. The clinical introduction of several high performing diagnostic tests is helping to redefine patient management. It is well-known that Aspergillus antigen can be detected in 70-95% of bronchoscopy samples in patients with invasive and chronic aspergillosis in less than 1 hour. Aspergillus immunoglobulin G (IgG) (precipitins) is >90% sensitive and >85% specific for chronic and allergic aspergillosis. High-volume respiratory fungal culture and Aspergillus polymerase chain reaction have 3-5-fold higher sensitivity than routine bacterial culture. Aspergillus IgE (or skin prick testing) diagnoses Aspergillus sensitisation in asthma, cystic fibrosis, chronic obstructive pulmonary disease and post-TB, and correlates well with poorer lung function and/or exacerbations. Clinicians and laboratorians across the world need to mainstream these excellent new tools to improve clinical outcomes by delivering results in a more timely and accurate fashion.